i have two ethernet cards on my linux machine ( server which is surving internet), i have two internet connections from diff isp i need redundancy between both of them on client side with out changing gateway on client side how can i do it can anyone help me

well, that one is quite tricky since there's only one field on every nic spared for a gateway.

Am sure that could only be possible by addressing your ips with all necessary ips but what matters on internet surfing normally after setting up your nic card is the way your browser's internet options are configured.

If both nics are able to use 'dhcp' I guess that quite easy to get what you need. but if they boy use different internet options i.e. one uses 'dhcp' the other passes thru a proxy server, then you gonna have to install an extra internet browser such as mozilla and may be IE. coz with both you can configure them different so that one internet browser can be used to surf using one nic and the other too used to surf internet using the other configuration from the second nic.

try that one and let me know.

how are the 2 NICs connected?
1. to LAN
2. to Switch -> Router?

that is adsl connection from two different isps
both of them i have connected from adsl router to switch and from there i have connected my eth card

ROUTER1 -> eth0
ROUTER2 -> eth1 ?

ADSLROUTER>to eth0 ethernetcard>ETH1 is connected to Switch

eth0=publicip
eth1=local lanip

i have enabled masqurade on iptables and i have two scripts one for one isp and another one for another isp

if one isp is down i will manualy change the ip of eth0 and i will run the script which is related script i have given all my local lan pcs gateway my eth1 ip address

now i want to this automaticaly

hmm? perhaps a cronjob which checks if eth0 is "online" (dns lookup or similar,..).....just an idea! ;-)

interested in further propositions

i have found some good links for this


http://lartc.org/howto/lartc.rpdb.multiple-links.html
http://linux-ip.net/html/adv-multi-internet.html
http://linux.com.lb/wiki/index.pl?no...ltiple%20Links
http://www.linux.org/docs/ldp/howto/...w-HOWTO-8.html